Guidance

Environmental permits for ‘orphan’ waste effluent treatment plants: RPS 33

Updated 17 December 2025

Applies to England

This regulatory position statement (RPS) does not change your legal requirement to:

• have an environmental permit where one is required
• comply with the conditions of your environmental permit
• register an activity as exempt where you are required to do so

However, the Environment Agency will not normally take enforcement action against you if you do not comply with these legal requirements provided that :

• your activity meets the description set out in this RPS
• you comply with the conditions set out in this RPS

In addition your activity must not cause (or be likely to cause) pollution of the environment or harm to human health, and must not:

• cause a risk to water, air, soil, plants or animals
• cause a nuisance through noise or odours
• adversely affect the countryside or places of special interest

Activity this RPS applies to

This RPS applies to ‘orphan’ waste effluent treatment plants.

Examples of ‘orphan’ waste effluent treatment plant covered by this RPS include:

• leachate treatment plant at historic landfills which no longer have, or never had, an environmental permit
• small manufacturing sites that do not exceed the threshold for a Part A (1) installation under the Environmental Permitting Regulations

This RPS does not apply where the activity is carried on as part of another activity which requires a permit.

Conditions you must comply with

You must:

• only treat liquid waste or wastewater produced on site
• classify the effluent if you export it from your site – see waste classification technical guidance WM3 
• notify the Environment Agency by email at wastetreatment@environment-agency.gov.uk before you use this RPS
• keep records for 2 years from the date of the last use of the RPS to show that you have complied with this RPS and make these records available to the Environment Agency on request

You must also comply with the conditions in your:

• trade effluent consent if you discharge effluent to the sewerage system
• stand-alone water discharge activity permit for discharge to surface water
• groundwater activity permit for discharges to groundwater 

You must not:

• import liquid waste from other sites
• treat effluent using anaerobic digestion

Things to note

A waste effluent treatment plant is ‘orphan’ if the activity it serves is not regulated under the Environmental Permitting (England and Wales) Regulations 2016 and one of the following applies:

• the discharge of the treated effluent is authorised by a Water Industry Act trade effluent consent or an Environmental Permitting Regulations schedule 21 stand-alone water discharge permit 
• the treated effluent is sent off site for further treatment or disposal

When you must check back

The Environment Agency will review this RPS by 31 December 2027.

The Environment Agency can withdraw or amend this regulatory position before the review date if they consider it necessary. This includes where the activity that this RPS relates to have not changed.

You will need to check back from time to time, including at and before the review date, to see if this RPS still applies.

This RPS remains in force until it is removed from GOV.UK or is otherwise identified as having been withdrawn.

You can subscribe to email updates about this RPS. These will tell you if the RPS has changed and when it has been withdrawn.

If you cannot comply with this RPS

If you operate under this RPS but can no longer comply with it, you must:

• stop the activity to which this RPS relates
• tell the Environment Agency immediately by contacting wastetreatment@environment-agency.gov.uk with RPS 33 in the subject

Contact the Environment Agency

If you have any questions about this RPS, email wastetreatment@environment-agency.gov.uk with RPS 33 in the subject.